Safety attachment for machine tools



Dec. 2, 1930. o. L. KLUGH ET AL 1,733,476

Y SAFETY ATTACHMENT FOR MACHINE TOOLS Filed Jan. 16, 1930 F161. D F1112. m

' INVENT 0R3 0RMON 1.. hLl/GH THOMAS E. HAVERSTICIL Patented Dec. 2, 1930 UNITED STATES PATENT OFFICE onMoN L. KLUGH AND THOMAS E. HAVEBSTICK, or MUNCIE, INDIANA SAFETY ATTACHMENT FOR MACHINE TOOLS Application filed January 16,1930. Serial No. 421,265.

Our invention relates to safety attachments for machine tools of the type in which a series ofboring bits closely spaced, and which are retained in a head member therefor, are

'5 lowered to and raised from the work.' These bits, whether they are in inoperative status or are idling, or are being passed through and Withdrawn from the work,present danger of serious personal injury to the machine operative.

Advantages desiredin the use of a tool of the above description are that the danger of injury may beguarded against, and that the boring bits may be visible to the operator at 1 all times. These general advantages as well as helpful results presently to be pointed out, are accomplished by the new construction, combination and arrangement of parts described in the following specification, and

' 2 illustrated in the accompanying drawings.

The invention is defined in the appended claims. g

The several parts of our invention are identified by suitable characters of reference applied to them in the different views in the drawings, in which- Figure 1 is a front view of our improved safety attachment.

F'gure 2 is a side view of the invention as seenin the direction of arrow 2 in Figure 1.

Figure 3 is a side view, as seen in the direction of arrow 3 in Figure 1.

Figure 4 is a rear view of Figure 1.

Figure 5 is a .sectional top plan view taken on the line 5-5 in Figure 1.

Figure 6 is a sectional top plan view taken on the line 66 in Figure 1. j y

Figure 7 is an enlarged top plan view of the attachment device removed.j 1

A machine tool structure of conventional form comprises a usual frame member A having guideway heads B, and C, in whicha rotatively journaled shaft D is supported, and which" is driven at the desired speed, and which is also capable of being lowered from and raised to its normal position. a

A tool head member G of conventional typ shown, and which in this-instance is three and one-half inches in width, carries a series of boring bits H which are geared to a driving stem J, which is fastened in the chuck E of shaft D. A stay bar K which is secured in a lug G of said head member has lts free end slidingly engaged in a suitable vertical member M of the machine tool frame. The function of this stay bar, is to stay the head member against rotative movement. The said boring bits having sharply pointed ends closely adjacent to each other and their pro ecting cutting portions being in overlapping relation, present an unusualdanger of injury to the operative handling the machine, and the material to beworked on. Our invention comtemplates the providing of a yoke adapted to be secured to the head member in which the boring tools are carried, an upright shield member, U shaped in cross section plan, the body portion thereof being transparent, and the sides being pivotally connected to the sides of the yoke, and a connecting rod having its lower end pivotally connected to the lower portion of the shield,

its upper end being adapted to be secured to a fixed superposed part of the machine tool.

The device thus constituted effectively guardsthespace at the front and sides of the boring bits while the bits are at the raised or inop'erativepositions, permits full view of the bits at all stages of the operation thereof, and prevents possibility ofthe operators hand coming into contact with the bits at all stages of the operation, and during the withdrawing of the bits from the work and the return of the head member to the raised position.

The yoke, which may be of sheet or cast metal, preferably the latter, has the front portion 1,"and the sides 2 and 3, adapted to rest against the front and sides respectively of the machine tool headmember Gr. Hingedly connected to the rear edge of the side 2 is a back bar 4, provided with incurved central portiona. The free end of said back bar is provided with a flange 4b. Projected from said flange is a threaded stud lc. Formed integral with the rear edge portion of the side 3 of the yoke, is an ear 3a, having an inturne'd tooth 3b. A slot 30 is provided in said ear and is adapted to receive the stud, when the yo e is. to be attached to themachine tool head 10o member. The said stud is provided with a wing nut 5.

The shield member has its body portion 7 provided with a pane of material which permits the passing of light. The material preferred for this pane 8 is wire netting of about three sixteenths inch mesh. The sides 9 and 9 have their projected upper ends journaled on pintles 10 and 10 which are provided on the sides of the yoke. At the lower portion of one of the sides of the shield is a stud pin 12 which is provided with a cotter 13.

The connecting rod is of divided formation, consisting of sections 14: and 15. Fixed threaded studs 16 of one section are in engagement with the longitudinal slots 17 of the other section, and are provided with wing nuts 18. The connecting rod is journaled at its lower end, on the stud pin 12 of the shield, and being capable of adjustment as to length, the invention is adaptable to conform to variation in the distance, on different machines, between the head member G and the machine frame.

hereas the yoke, in the present embodiment of our invention, is shown in form specifically intended for a head member of the size and shape illustrated, it will be understood that modification in this feature, as well as in the other features of our invention may be made in conformity with special requirements incident to differences in forms and kinds of machines and of tool carrying head members.

The attachment, consisting of the yoke, the shield and the connecting rod, is furnished to the trade in knock down status, and it may be packed for handling and transportation in a container of relatively small size.

In installing the invention, the sections of the connecting rod are retained loosely in coengagement, by the wing nuts 18. The lower end of the said rod is ournaled on the stud pin 12 of the shield, and is there retained by a cotter 13. The yoke whose bar 4: is in open status, is then disposed in engagement with the head member G. The bar 4 is then swung to closed position as shown in Figures 5 and 7. Pressing of the bar 4: to the said position causes the portion 4a thereof to directly engage the back of the head member, the flange 4?) latching underneath the tooth 3?). Tightening then of the wing nut 5 causes the yoke to be clamped to tenacious union with the said head member. The upper section 14L of the connecting rod is readily disposed in position, with its slotted plate 20 in registration with the stud P of the machine frame, and to which said stud it is secured by a nut P. After the lower section 15 of said connecting rod will have been attached to the stud 12, and the shield will have been set at the substantially vertical position shown in Figure 2, the nuts 18 are tightened, the sections of the connecting rod being thereby securely united.

We prefer that these sections 14; and 15 be made of resilient metal, and that a detail of connection at the machine tool frame be of substantially the character as shown in F i gure 2. A connecting rod so constructed and so secured in place serves to hold the shield member firmly, and against vibration.

The invention installed, appears as shown in the drawings, the head member G in which the boring bits are retained being at the normal or raised position. A clear view through the transparent pane of the shield at the front and sides, and at a plane below the bottom. of the boring bits, is afforded.

The board Q, to be operated upon, is disposed on the bench R, and at proper position. Vith the lowering of the head member G the shieldwill have been swung forwardly to the position shown bythe dotted lines. During such movement forwardly of the shield, a guarding against danger of contact with the bits is maintained, and at the same time a clear View of the bits, and of the portion of the board being operated upon, is afforded. hen the boring operation will have been completed and the head member will have been returned to the raised position the shield will have been automatically returned to the lowered and vertical position shown in the drawings.

WVe wish it to be understood that modifications may be made in the several structural features of our invention without departing from the spirit thereof or sacrificing any of its advantages.

Vhat we claim as our invention is- 1. An attachment for machine tools, comprising a yoke adapted to be secured to the movable head member of a machine tool, a shield member U shaped in cross section, the frontal portion thereof being of transparent material, and the sides thereof being pivotally connected at their upper portions to said yoke, and a connecting member having its lower end pivotally connected to the lower portion of the shield and its upper end being adapted to be secured to a fixed part of the machine tool.

2. An attachment for machine tools, comprising a frame member adapted to be removably secured to the movable head member of the machine tool, a shield member U shaped in cross section, the sides thereof at their upper portions being pivotally connected to the said frame member, and the frontal portion thereof being cut out and provided with a netting, and a divided connecting rod, one section thereof being slidable on the other, the lower section being pivotally connected to the lower portion of the shield, and the upper section being adapted to be secured to a fixed part of the machine tool, and adjustable fastenings between the sections of the connecting rod.

3. An attachment device for machine tools comprising a yoke adapted to be secured to the movable head member of the machine tool, a transparent shield member having sides to register at planes adjacent to the sides of the yoke, and being pivotally connected at its upper portion to said yoke, and connections between the shield member and a fixed part of the machine tool whereby the shield is swung from its Vertical position when the head member of the machine is lowered, and is swung to its vertical position when the head member of the machine is raised.

ORMON L. KLUGH.

THOMAS E. HAVERSTICK. 

